Method of killing plants



Patented Jan. 27, 1953 METHOD OF KILLING PLANTS Percy W. Zimmerman and Albert E. Hitchcock, Yonkers, N. Y., assignors to Boyce Thompson Institute for Plant Research, Inc., Yonkers, N. Y., a corporation of New York No Drawing. Application June 30, 1950, Serial No. 171,574

This invention relates to herbicides and has for its object the provision of an improved method of suppressing the growth of plants with a new herbicidal composition. Our invention is based upon the discovery that undecylenic acid and halogenated undecylenic acid, their salts, esters and amides and the corresponding aldehydes which oxidize readily to such acids have pronounced herbicidal properties. As used herein, the word suppressing refers to actual or complete killing and partial killing of the plant.

The. following undecylenates are especially effective herbicides: Undecylenic acid, methyl undecylenate, isobutyl undecylenamide, n-undecylenic aldehyde, brominated undecylenic acid, and polyethylene glycol (300) .undecylenate.

.. The aforementioned undecylenates are herbicides which kill many plants including most com. monweeds when applied to the foliage as a spray, especially an aqueous spray, for example, in concentrations of from 0.3% to The undecylenates are derived from undecylenic acid, a relatively inexpensive compound which may be produced in various ways, notably as a fraction of castor oil. The various derivatives of undecylenic acid may be prepared by means well known in the art. These compounds are relatively insoluble in Water but may be dispersed in water "with suitable solubilizers and emulsifiers. Suitable compositions comprising the compound dispersed in water may be prepared by adding, for example, Solvesso 100 oil, Cellosolve, and Emulfor Ela, to the undecylenate and diluting with water.

The results of the application of aqueous spray compositions of undecylenic acid in various concentrations to many weeds and crop plants are illustrated in Table I. In carrying out a method of the invention, the results of which are reported in Table I, the foliage of the plants was treated with an aqueous spray in which undecylenic acid was dispersed by means of Solvesso 100 oil. Table I shows that undecylenic acid does not kill plants outright in concentrations below around 0.3%; however, in higher concentrations it is an 6 Claims. (01. 71-217) effective killer. Undecylenic acid does not kill grasses in relatively low concentrations but in proper dosage will kill crabgrass without noticeable injury to lawn grasses.

The undecylenates of the invention may be used very efiectively in compositions comprising 2,4-D or'chloropicrin. The effect is either synergistic or mutual activation. In any event, the mixtures are more effective than the separate efiects of the compounds. Table II shows the results of combining undecylenic acid and 2,4-D.

The tests of Tables I and II were based upon treatment of plants in greenhouses. The same tests have been carried out on plants in the field with surprisingly better results than the greenhouse tests.

At the present time there is no satisfactory herbicide for applying to the weeds in rows of growing vegetables, such as potatoes, carrots, cabbage, beans, and the like.fwhere it is necessary to follow one crop with another. The compounds of the invention exhibit no objectionable residual effect. In fact, seeds can be planted the day after spraying the soil. The compoundsproduce rapid killing and do not impart any objectionable taste to vegetables sprayed between the rows. The compounds may be applied in such concentrations as to effect a mere defoliation or to the flowers or young set fruit (calyx stage) to effect blossom or fruit thinning. They may be. applied, for example, to, potato vines just before harvesting to kill the vines, without injury to the tubers.

Chloropicrin may be included in the compositions of undecylenates to intensify the action of the composition. Chloropicrin is especially eifective in the composition to kill soil-borne fungus such as S. rolfsiz' which produces a blight on plants. In the composition, the fungicidal properties of the chloropicrin are intensified. Table III shows the effect of using compositions com-' prising chloropicrin and undecylenic acid.

Our application Serial No. 171,572, filed June 30, 1950, covers compositions comprising undecylenic acid and chloroacetic acid.

TABLE I Minimum percentage concentrations of undecylenic acid sprays efiective for inducing the responses indicated.

Column Number 1 2 3 4 5 Species Complete Complete Severe Slight plant top foliage foliage Noiniury killing killing injurv injury 1 \Vecds:

Clover 1. 0 1. 0 0. 32 0. 32 0.1 Chickweed. s. 2 1. 0 0. 32 0. 32 0. 1 01-3115 3.2 1.0 0.32 0.1 0.032 Galinsogii... 3. 2 1. 0 0.32 0. 32 0. 32 Amaranthus. 1.0 1.. 0 0. 32 0. 32 0. 32 Chenopodi11m 1. 0 1. 0 0. 32 0. 32 0. 1 smartweedin 3.2 3.2 1.0 0.32 0.1 Purslane... 1. 0 1. 0 0.32 0.32 0. 32 Crab grassnin 3. 2 1. 0 0.32 0. '12 0. 32 Water hyacinth 3. 2 3. 2 1. 0 1. 0 1. 0 Alligator Weed 32 3.2 1.0 10 Wild carrot" 1. 0 1. 0 0.32 0;32 0. 32 A1gae 1.0 1.0 1;0 1.0 1.0 Crop Plants Tomato. 1.0 1. 0 0. 82 0. 32 0.1 3-4" corn 1.. 3. 2 3.2 0.32 0.1 0.032 18-24" corn (basa1).. 3. 2 3. 2 1.0 1.0 1.0 Gladislus 3. 2 3. 2 1. 0 1. 0 1. 0 12" peach sced1ings 3. 2 3. 2 3. 2 1. 0' 1. 0 Pine seedlings 3. 2 3. 2 1. 0. 1. 0 1. 0 10 10 1.0 1.0 1.0 10 10 10 10 1.0 1. 0 1. 0 1. 0 1. 0 1. 0 1.0 1.0 1.0 1.0 1.0 3. 2 1.0 0.32 0.1 0. 032 3. 2 1. 0 0. s2 0. 32 0. 1 Buckwheat 3. 2 1. 0 1. 0 0. 32 0. 1

Norm-Apparently not translocated. 1 Considered tolerant.

TABLE II 2. In the method of claim 1, applying the com- Increased efiectz'veness in killing due to composi- 5 2 :3 fig g i as to km only tions 2,4-D and undec lenic aoi of y d 3. In the method of 018.1111 1, applying the com- 40 position in such a concentration as to kill the Percolntagegoilicentration entire plant.

t x0 aci a one or in mixtures Percentage Timeto km 4. The method 01 suppress ng the growth of plants killed (days) plants which comprises applying to the plant a Undecylenic 2A4) compositlon compnsmg an undecylenateof the group conslstmg of undecylenic acid, methyl un- 10 6G 14 decylenate, isobutyl undecylenamicle, n-undecy- 0.1 100 13 lenic aldehyde, brominated undecylenic acid, and 6:2 '8 polyethylene glycol (300) undecylenate in water g at a concentration of from 0.3% to 10%.

1 55 14 5. In the method of claim 4, applying the comg position in such a concentration as to kill only a part of the plant.

6. In the method of claim 4 a l in TABLE III p y gthecom position 1n such a concentration as to kill the entire plant; Mortality gt siclfirotia in s iiitrc- PERCY W ZIM R N Mixture used in soil ce'wmgt 9 O owmg i lets MIE MIA croifi ofifi A ALBERT E. HITCHCQCK.

1 2 3 .07 .20 .60 1.20 50 REFERENCES CITED Mp Acid The following references are of record in the file of this patent: Percent Percent Percent Percent Peibcent Pegcent Pcggent 15 85 0 5 15 125 82 5 9O 95 UNITED STATES PATENTS check 0 Number Name D t 2,390,941 Jones Dec. 11, 1945 We claim: 1. The method of suppressing the growth of OTHER REFERENCES plants which comprises applying to the plant a Chemical bsfi o s, v01. 42, column 3803h composition comprising undecylenic acid dispersed in water at a concentration of from 0.3% to 10%.

(1948), abstract of article by Brodersen et al. The Chemistry and Uses of Insecticides," De Ong (1948), pages 173 and 1'74. 

1. THE METHOD OF SUPPRESSING THE GROWTH OF PLANTS WHICH COMPRISES APPLYING TO THE PLANT A COMPOSITION COMPRISING UNDECYLENIC ACID DISPERSED IN WATER AT A CONCENTRATION OF FROM 0.3% TO 10%. 